Large scale network service providers often utilize multiple server computers to respond to network requests from users and client devices. In many cases, the server computers administer and interact with databases using relational database management systems (RDBMSs). A typical Internet web site may be supported by hundreds or thousands of physical or virtual server computers and corresponding RDBMSs, which may be part of a server farm or data center in which the server computers are connected to each other using high-speed local-area networking (LAN) technologies.
Memory is an important resource for an RDBMS. When there is insufficient main memory, an RDBMS is forced to use relatively slow mass media storage devices such as hard disk drives (HDDs) or solid-state drives (SSDs), which can result in significant performance degradation.